X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FTyCon.lhs;h=7d114820c206acefb6d2dd09ab183adf8d3843d2;hb=34429d31b0d48352e4ffd29186e919b6248cdd5c;hp=87ae25d1ca8eeabcf4c29c429cfd4a0b75187165;hpb=25f84fa7e4b84c3db5ba745a7881c009b778e0b1;p=ghc-hetmet.git

diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs
index 87ae25d..7d11482 100644
--- a/compiler/types/TyCon.lhs
+++ b/compiler/types/TyCon.lhs
@@ -256,6 +256,8 @@ data AlgTyConRhs
 				-- See Note [Newtype coercions]
 				-- Invariant: arity = #tvs in nt_etad_rhs;
 				--	See Note [Newtype eta]
+				-- Watch out!  If any newtypes become transparent
+				-- again check Trac #1072.
 
 	nt_etad_rhs :: ([TyVar], Type) ,
 			-- The same again, but this time eta-reduced
@@ -475,6 +477,7 @@ data PrimRep
   | AddrRep		-- a pointer, but not to a Haskell value
   | FloatRep
   | DoubleRep
+  deriving( Eq )
 
 -- Size of a PrimRep, in bytes
 sizeofPrimRep :: PrimRep -> Int
@@ -814,7 +817,7 @@ tcExpandTyCon_maybe, coreExpandTyCon_maybe
 		  Type,			-- Body type (not yet substituted)
 		  [Type])		-- Leftover args
 
--- For the *typechecker* view, we expand synonyms only
+-- For the *typechecker* view, we expand (closed) synonyms only
 tcExpandTyCon_maybe (SynTyCon {tyConTyVars = tvs, 
 			       synTcRhs = SynonymTyCon rhs }) tys
    = expand tvs rhs tys